Electronic information device having a display and method and apparatus for controlling power-off of the display

ABSTRACT

An electronic information device which uses a memory card to which a liquid crystal display using liquid crystal with a memory effect is attached. If a command to turn off the electric power source is issued during writing of information on the liquid crystal display, a power-off process is executed after completion of the writing. This electronic information device is adapted, for example, to be used as a digital camera.

This application is based on application No. 11-78117 filed in Japan,the content of which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to various kinds of electronic informationdevices such as digital cameras, TV sets, personal computers, electronicbooks, man-machine interfaces, etc, and a control method of such adevice.

2. Description of Related Art

With development of electronic information devices which require adisplay section to display images, such as computers, digital cameras,etc., various display devices using materials with a memory effect havebeen developed. For example, Japanese Patent Laid Open Publication No.8-317324 describes an embodiment of adopting ferrodielectric liquidcrystal to an electronic camera. Japanese Patent Laid Open PublicationNo. 10-197850 describes an embodiment of using ferrodielectric liquidcrystal in a display device for a pen computer so as to save energy.

Such a display device using a material with a memory effect has anadvantage of consuming no electric power in maintaining a picture on thedisplay, while consuming electric power in writing information on thedisplay. For example, Japanese Patent Publication No. 7-101336 disclosesthat a supply of electric power to a display panel with a memory effectis shut off after the display panel has made a display of a calendar, apicture, etc.

In the display device disclosed by Japanese Patent Publication No.7-101336, however, if a supply of electric power is shut off duringimage writing on the display, an incompletely written picture stays onthe display, which is ugly. Thus, in such a display device using amaterial with a memory effect, the display sequence must be changed.There is no prior art which focuses on a power-down during image writingon a display with a memory effect. If a supply of electric power is shutoff suddenly, there may be a case that an incompletely written image isdisplayed continuously. In order to avoid such trouble, it is necessaryto time a power-down of the display section to completion of imagewriting on the display, which is inconvenient.

Conventionally, only ferrodielectric liquid crystal is regarded as amaterial with a memory effect. Recently, however, cholesteric liquidcrystal and chiral nematic liquid crystal start to be used practically.For example, U.S. Pat. No. 5,625,477 discloses a method of displaying amulti-tone image on chiral nematic liquid crystal.

Accordingly, in the art of display devices using materials with a memoryeffect, it is required to improve the control of image writing and poweroff so as to display a complete picture at all times. Further, in theart of electronic information device used as a man-machine interfacewhich has an input section (including a power switch) with which anoperator inputs a specified command and a display section with a memoryeffect, it is necessary to improve the association of the input sectionwith the display section to improve the operability.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an electronicinformation device with a memory effect which never displays anincomplete picture continuously, and a control method of the electronicinformation device.

Another object of the present invention is to provide an electronicinformation device wherein an input section to be operated by anoperator and a display section with a memory effect are associated welland which can be easily operated.

In order to attain the objects, an electronic information deviceaccording to the present invention comprises: a display which uses amaterial with a memory effect; an electric power source which suppliesdriving power to the display; and a controller which, in response to acommand to turn off the electric power source which is issued while thedisplay is performing writing by consuming electric power supplied fromthe electric power source, turns off the electric power source aftercompletion of the writing. The controller may be one which, when anautomatic power-off process is commanded while information is beingwritten on the display, turns off the electric power source aftercompletion of the writing.

With the arrangement, even if a power-off command is issued duringwriting on the display or even if an automatic power-off system worksfor energy saving, supply of electric power to the display is continueduntil completion of the writing. Accordingly, it never occurs that anincomplete picture is continuously displayed. Especially, wheninformation is written based on image data, because it has a largevolume and requires a long time to be displayed, the delay of executionof a power-off is effective.

Another electronic information device according to the present inventioncomprises: a display using a material with a memory effect; a firstinput member with which an operator inputs a specified command; and acontroller which, when the first input member is operated during writingon the display, invalidates the command sent from the first input memberand, when the first input member is operated after completion of thewriting, controls the electronic information device in accordance withthe command sent from the first input member. In a display which uses amaterial with a memory effect, it takes a time to write informationthereon. If a command from the first input member is accepted duringwriting, the writing will be discontinued and repeated from thebeginning, which is inefficient. According to the present invention,since a command which is sent from the first input member during writingon the display is invalidated, the efficiency and the convenience of thedevice are improved.

There are, however, commands which shall be accepted regardless ofwhether or not writing on the display is being performed. For example,in a digital camera, it is preferred to accept a command sent from ashutter button even during writing on the display so as not to miss ashutter chance.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and features of the present invention will beapparent from the following description with reference to theaccompanying drawings, in which:

FIG. 1 is a sectional view of an exemplary liquid crystal display to beemployed in a data storage medium;

FIG. 2 is a plan view which shows a state of forming a columnarstructure and a sealant on a substrate of the liquid crystal display;

FIG. 3 is a block diagram showing a driving circuit of the liquidcrystal display;

FIG. 4 is an illustration of a driving method of the liquid crystaldisplay;

FIG. 5 is a perspective view of a first memory card which is used for anelectronic information device according to the present invention;

FIG. 6 is a block diagram showing a circuitry of the memory card;

FIG. 7 is a perspective view of a second memory card;

FIG. 8 is a block diagram showing a circuitry of the memory card shownby FIG. 7;

FIG. 9 a is a perspective view of a liquid crystal display mounted on asupport;

FIG. 9 b is a perspective view of a supported liquid crystal displaybeing inserted into a recess in a memory card;

FIG. 9 c is a perspective view of the memory card having the liquidcrystal display inserted therein;

FIG. 10 is a perspective view of a fourth memory card;

FIG. 11 is a sectional view of the memory card shown by FIG. 10;

FIG. 12 is a block diagram of a circuitry of the memory cards shown byFIGS. 9 and 10;

FIG. 13 is a block diagram showing a driving circuit of the liquidcrystal display;

FIG. 14 is a front view of a first exemplary digital camera according tothe present invention;

FIG. 15 is a rear view of the digital camera;

FIG. 16 is a side view of the digital camera;

FIG. 17 is a bottom view of the digital camera;

FIG. 18 is a block diagram showing a control circuit of the digitalcamera;

FIG. 19 is an illustration showing the state of the liquid crystaldisplay before a format process;

FIG. 20 is an illustration showing an exemplary format of the liquidcrystal display;

FIG. 21 is a flowchart showing a control procedure right after power-onof the digital camera;

FIG. 22 is a flowchart showing a control procedure of the liquid crystaldisplay;

FIG. 23 is an illustration of a thumbnail picture on the liquid crystaldisplay;

FIG. 24 is an illustration showing exemplary pictures to be displayed ona LCD section of the digital camera;

FIG. 25 is a rear view of a second exemplary digital camera according tothe present invention;

FIG. 26 is a bottom view of the digital camera shown by FIG. 25;

FIG. 27 is an illustration showing another exemplary format of theliquid crystal display;

FIG. 28 is a flowchart showing a control procedure of the liquid crystaldisplay in the second exemplary digital camera;

FIG. 29 is a flowchart showing a control procedure of the secondexemplary digital camera in a photography mode;

FIG. 30 is an illustration of another exemplary picture on the liquidcrystal display;

FIG. 31 is a flowchart showing a control procedure of the secondexemplary digital camera in a reproduction mode;

FIG. 32 is an illustration showing another exemplary picture on theliquid crystal display;

FIG. 33 is a flowchart showing another control procedure of the secondexemplary digital camera in the photography mode;

FIG. 34 is an illustration showing another exemplary picture on theliquid crystal display;

FIG. 35 is a block diagram showing the structure of a timing controller;and

FIGS. 36 and 37 are flowcharts showing a control procedure in thephotography mode including an automatic power-off process.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Some embodiments of an electronic information device and a controlmethod thereof according to the present invention are described withreference to the accompanying drawings.

General Structure of Memory Card with Memory-Effective Liquid Crystal

First, a memory card which is provided with liquid crystal with a memoryeffect (which will be hereinafter referred to as a memory card withmemory-effective liquid crystal) is described. The memory card is basedon the PCMCIA type 2 standard, and when the memory card is used, it isinserted in a PCMCIA card slot of a digital camera or a personalcomputer. The memory card comprises a memory section and a displaysection. For the memory section, a conventional flash memory is used,and for the display section, a liquid crystal composition which has amemory effect and exhibits a cholesteric phase at room temperature(which will be hereinafter referred to as cholesteric liquid crystal) isused.

Display Principle of Memory-Effective Liquid Crystal

First, a liquid crystal display device used as the display section isdescribed. The liquid crystal display device comprises a liquid crystaldisplay which has cholesteric liquid crystal between substrates and adriving section thereof. FIG. 1 is a sectional structural view of anexemplary liquid crystal display 10.

In FIG. 1, the numerals 11, 12, 13 and 14 are transparent substrates. Onthe front and back surfaces of these transparent substrates, a pluralityof strip-like transparent electrodes 15 and 16 are provided. Theelectrode strips 15 extend in parallel to one another, and the electrodestrips 16 extend in parallel to one another with the extending directionof the electrode strips 15 and the extending direction of the electrodestrips 16 being perpendicular to each other. In short, the electrodes 15and 16 are arranged in a matrix. A voltage is applied to theintersections of the electrodes 15 and 16, and these intersectionsfunction as pixels. The numeral 17 is a columnar structure composed ofcolumns which are arranged entirely in the transparent substrates amongthe pixels at regular intervals (or maybe at random) (see FIG. 2). Thenumeral 18 is a cholesteric liquid crystal composition. The numeral 19is a sealant to seal the liquid crystal composition 18 in thetransparent substrates. If necessary, insulating layers and alignmentcontrolling layers may be provided on the transparent electrodes 15 and16 on the substrates 11 through 14.

The liquid crystal display 10 has a red display layer R, a green displaylayer G and a blue display layer B which are placed one upon another inthis order on a light absorber 20. The red display layer R makes adisplay by switching between a red selective reflection state and atransparent state. The green display layer G makes a display byswitching between a green selective reflection state and a transparentstate. The blue display layer B makes a display by switching between ablue selective reflection state and a transparent state.

In the liquid crystal display 10, the liquid crystal performs selectivereflection when it is in a planar state and becomes transparent when itis in a focal-conic state. By switching the liquid crystal between thesestates, the liquid crystal display 10 makes a display. When the liquidcrystal is in a planar state, it selectively reflects light of awavelength λ=Pn (P: helical pitch of the cholestric liquid crystal, n:average refractive index of the liquid crystal).

If the wavelength of light selectively reflected by the cholestericliquid crystal is within the infrared spectrum, when the liquid crystalis in a focal-conic state, it scatters visible light. If the wavelengthof light selectively reflected by the cholesteric liquid crystal isshorter than the infrared spectrum, the liquid crystal, in a focal-conicstate, transmits visible light. Accordingly, by providing a lightabsorber 20 on the side of the liquid crystal display 10 opposite theobserving side (indicated by arrow “A”) and by setting the wavelength oflight selectively reflected by the liquid crystal within the visiblespectrum, display of a specified color (made in a planar state) andblack (made in a focal-conic state) is possible. Also, by setting thewavelength of light selectively reflected by the liquid crystal withinthe infrared spectrum, display of black (made in a planar state) andwhite (made in a focal-conic state) is possible.

By applying a voltage of a first threshold value Vth1 which is thethreshold voltage to untwist the cholesteric liquid crystal for asufficient time and thereafter dropping the voltage lower than a secondthreshold value Vth2 which is smaller than Vth1, the liquid crystalcomes to a planar state. Also, by applying a voltage higher than Vth2and lower than Vth1 to the liquid crystal for a sufficient time, theliquid crystal comes to a focal-conic state. These states can bemaintained even after application of a voltage is discontinued It hasbeen known that there is a state where these two states are mixed andthat a display of intermediate tones is possible (refer to U.S. Pat. No.5,384,067).

As FIG. 3 shows, the pixels of the liquid crystal display 10 arestructured in a matrix composed of a plurality of scan electrodes R1, R2through Rm and data electrodes C1, C2 through Cn (m, n: naturalnumbers). The scan electrodes R1 through Rm are connected to outputterminals of a scan electrode driving circuit 21, and the dataelectrodes C1 through Cn are connected to output terminals of a dataelectrode driving circuit 22.

The scan electrode driving circuit 21 outputs a selective signal tospecified ones of the scan electrodes R1 through Rm so as to set thespecified scan electrodes to a selected state while outputting anon-selective signal to the other scan electrodes so as to set the otherscan electrodes to a non-selected state. The scan electrode drivingcircuit 21 outputs the selective signal to the scan electrodes R1through Rm in order while switching at regular intervals. In themeantime, the data electrode driving circuit 22 outputs a signal inaccordance with image data to the data electrodes C1 through Cn forrewriting of the pixels on the scan electrodes in a selected state. Forexample, when a scanning electrode Ra (a: natural number, a≦m) isselected, displayed information on the pixels LRa-C1 through LRa-Cn atthe intersections of the scanning electrode Ra and the data electrodesC1 through Cn is rewritten. Thus, in each pixel, the difference betweenthe voltage applied to the scan electrode and the voltage applied to thedata electrode is a rewriting voltage, and each pixel is rewritten inaccordance with this rewriting voltage.

Referring to FIG. 4, displaying an image of which image data areexpressed by a matrix [Pij] composed of m rows and n columns isdescribed. First, a pulse voltage in accordance with data for the firstline indicated by row vectors P11, P12 . . . P1 n is applied to the dataelectrodes C1, C2 . . . Cn, while only the scan electrode R1 selectedfrom the scan electrodes R1 through Rm is charged to a specifiedvoltage. Thereby, the pixels in the first line, namely, L11, L12 . . .L1 n come to a planar state or to a focal-conic state. Thereafter, whenthe application of voltage to the scan electrode Ra is stopped, thedisplay states of the pixels L11, L12 . . . L1 n are maintained.

In the same way, a pulse voltage in accordance with data for the “i”thline indicated by row vectors Pi1, Pi2 . . . Pin is applied to the dataelectrodes C1, C2 . . . Cn, while only the scan electrode Ri selectedfrom the scan electrodes R1 through Rm is charged to the specifiedvoltage. Thereby, the pixels in the “i”th line, namely, Li1, Li2 . . .Lin come to a planar state or to a focal-conic state. Thereafter, whenthe application of voltage to the scan electrode Ri is stopped, thedisplay states of the pixels Li1, Li2, . . . Lin are maintained. Byapplying this procedure to all the “i” (1≦i≦m) lines repeatedly, theimage [Pij] is completely displayed, and the display state ismaintained.

By carrying out the above-described matrix drive toward the displaylayers B, G and R in order or simultaneously, a full-color image can bedisplayed on the liquid crystal display 10. Further, by driving theliquid crystal with the image data [Pij] changed as time goes by,display of a motion picture is possible.

Materials for Liquid Crystal Display and Producing Method Thereof

As the transparent substrates, transparent glass substrates and polymerfilms can be used. The polymer films mean, for example, resin such aspolyether sulfone, polycarbonate, polyethylene terephtalate.

As the electrodes, transparent electrodes such as ITO, NESA coat, etc.are usable, and such a material is formed into the electrodes bysputtering or vapor deposition. The lowermost electrodes may be blackelectrodes so as to also function as a light absorber.

As the liquid crystal composition, it is preferred to use a materialwhich exhibits a cholesteric phase at a room temperature. What is suitedas the material is chiral nematic liquid crystal which is produced byadding a chiral agent to nematic liquid crystal. Although nematic liquidcrystal is not limited to the followings, mixtures mainly containingliquid crystalline tolan compounds, liquid crystalline pyrimidinecompounds, liquid crystalline ester compounds, liquid crystalline cyanobiphenyl compounds, liquid crystalline phenylcyclohexyl compounds,liquid crystalline tarphenyl compounds or mixtures of these compoundscan be named as specific examples of nematic liquid crystal. Variouscoloring agents, e.g. dichroic dyes may be added to the liquid crystalcomposition.

As the columnar structure, for example, thermoplastic resin is usable.The requirements as the material of the columnar structure are to besoftened by heating and hardened by cooling, not to chemically react tothe liquid crystal material and to have appropriate elasticity. Althoughthe columnar structure serves as a spacer to maintain the gap betweenthe substrates, spherical spacers made of an inorganic material, whichare conventionally used, may be also used as well as the columnarstructure.

Structure of Memory Card with Memory-Effective Liquid Crystal

There are two types of memory cards which have a display section usingliquid crystal with a memory effect, namely, a memory section/displaysection integrated type and a memory section/display section separatetype.

Memory Section/Display Section Integrated Type

FIGS. 5 and 6 show a memory card 40 which is based on the PCMCIA type 2standard. On a substrate (not shown) in a metal card case 41, flashmemories 43, 44, a driving circuit 45 comprising an address decoder, theabove-described liquid crystal display 10 and its driving circuits 21and 22 are arranged. On the liquid crystal display 10, a transparentplastic window 42 is provided. On an end surface of the case 41, aconnector 46 of the PCMCIA standard is provided. When this memory card40 is used, it is fitted in an electronic information device with aconnector of the PCMCIA standard, such as a digital camera, a personalcomputer or the like, in the direction “X”.

Electric power is supplied to the memory card 40 from the electronicinformation device. However, because the display section comprisesliquid crystal with a memory effect, even when the memory card 40 istaken out of the electronic information device and is not supplied withelectric power, the liquid crystal display 10 is capable of keeping adisplay thereon. Descriptions of display modes will be given later. Theconnector 46 functions not only to input and output electric power and asignal to and from the memory section but also to input and outputelectric power and a drive signal to and from the driving circuits 21and 22 of the liquid crystal display 10.

Memory Section/Display Section Separate Type

The memory section/display section separate type memory cards can befurther divided into two type, namely, an adapter type which permits useof conventional memory cards (without the liquid crystal display 10) anda display section sticking type which facilitates an exchange of liquidcrystal displays when the liquid crystal display 10 ages and degrades.

Adapter Type

FIGS. 7 and 8 show a compact flash memory card 50 which is widely usedas a data storage medium for a digital camera and a PC card adapter 52for the memory card 50. The PC card adapter is provided with theabove-described liquid crystal display 10. The picture on the display 10can be seen through a transparent plastic window 53. The memory card 50is fitted in a frame 54 of the adapter 52 in the direction “X₁”.Thereby, a connector 51 connected to the driving circuit 45 comes incontact with a connector 55 provided on the adapter 52. The connector 55is connected to a connector 46 which is provided on an end surface ofthe adapter 52. In FIGS. 7 and 8, the same members are denoted by thesame reference symbols as those in FIGS. 5 and 6.

Display Section Sticking Type

As FIG. 9 b shows, on a surface of a casing 57 of a compact flash memorycard 56, a recess 58 in which a display section is to be placed isformed. In the recess 58, electrodes 59 for a drive of the displaysection are formed. The liquid crystal display 10 is joined to a support25 integrally. On the reverse side of the support 25, electrodes 26which are electrically connected to the driving circuits 21 and 22 areformed. When the center portion of the reverse side of the support 25 isstuck to the recess 58 by a double-side sticky tape or an adhesive, theelectrodes 26 and 59 are electrically connected to each other.

The recess 58 has a projection 58 a, and the support 25 has a cut-out 25a. In fitting the liquid crystal display 10 in the casing 57, thecut-out 25 a must be engaged with the projection 58 a, and there is nopossibility that the liquid crystal display 10 may be fitted in a wrongway. The support 25 is slightly smaller than the recess 58. The depth ofthe recess 58, the thickness of the electrodes 26 and 59, the thicknessof the support 25 and the thickness of the display 10 are so designedthat the surface of the display 10 will be on a level with the surfaceof the memory card 56 when the display 10 is fitted in the memory card56. Therefore, there is no fear that the liquid crystal display 10 maycome off when this memory card 56 is fitted in a digital camera or apersonal computer. Also, when the display section is to be changedbecause of aging or damage of the liquid crystal or by any reason, thechanging work is easy.

The display section may be inserted in the memory card through a slot.FIGS. 10 and 11 show an example of this way of fastening the displaysection to the memory card. In a casing 61 of a compact flash memorycard 60, a slot 62 is provided on the opposite side to the side wherethe connector 46 is provided. A display section, which comprises asupport 27 and the above-described liquid crystal display 10 fittedthereon, is inserted in the memory card 60 through the slot 62. Byinserting the display section in the direction “X₁” through the slot 62to the end, the electrodes 26 of the liquid crystal display 10 areelectrically connected to the electrodes 59 (see FIG. 12) provided inthe casing 61.

On a surface of the casing 61, a transparent plastic window 63 isprovided in a portion where the liquid crystal display 10 is to beplaced. Thus, when the display section is inserted in the memory card60, it can be used as a memory card with memorizable liquid crystal.Further, a lever 64 is provided on the casing 61 so that the displaysection can be taken out of the slot 62. This take-out mechanismcomprising the lever 64 is of a conventional type for a slot of thePCMCIA standard, and a description thereof is omitted.

FIG. 12 shows a circuit of a memory card of the memory section/displaysection separate type as shown by FIGS. 9 and 10. The same members ofthe circuit shown by FIG. 12 are denoted by the same reference symbolsas those in FIG. 6, and descriptions of these members are omitted.

Driving Circuit

Now referring to FIG. 13, a mechanism of displaying the content of imagedata on the liquid crystal display 10, especially the scan electrodedriving circuit 21 and the data electrode driving circuit 22 aredescribed in detail. FIG. 13 shows the members working for a drive ofthe liquid crystal display 10. Although the flash memories 43 and 44 areactually installed in the memory card, a driving circuit for thememories 43 and 44 is well-known, and a description thereof is omitted.

The memory card with memory-effective liquid crystal is based on thePCMCIA standard which is controlled by a CPU of a digital camera, apersonal computer or the like via a card interface. Accordingly, thememory card has four terminals, namely, a data bus, an address bus, acontrol bus and a power/grounding line although they are not shown. Whenan image is displayed on the liquid crystal display 10, a CPU of adigital camera, a personal computer or the like dispatches a writingcommand to the control bus, designates an address and outputs data.

In accordance with the output of data, first, image data for the firstline are stored in a line buffer 71. A timing controller 70 times sothat on completion of the storage, the image data for the first line canbe read out simultaneously for the respective columns and converted fromeight-bit data into analog image signals by D/A converters 72.

From an electric power source of the digital camera or the personalcomputer, a voltage of +5V is applied to this driving circuit via thememory card interface. In driving the liquid crystal display 10,however, in order to cause the liquid crystal to come to a focal-conicstate or a planar state, the voltage difference between the electrodesmust be a specified value. Therefore, the voltage is raised to aspecified value by a DC/DC converter 73 and then supplied to drivingbuffers 74. Thereby, the driving buffers 74 amplify the analog imagesignals sent from the D/A converters 72 and send the amplified signalsto the electrode columns C1, C2 . . . Cn.

In the meantime, the timing controller 70, at the timing of displayingimage data for the first line, sends a command to a decoder 75 to turnon only a switching circuit 76-1 and turn off the other switchingcircuits. When only the switching circuit 76-1 is turned on, the outputof the DC/DC converter 73 is applied to only the electrode row R1.Thereby, only the first line corresponding to the first electrode rowbecomes a display state in accordance with the image data. Because theliquid crystal has a memory effect, even after stoppage of theapplication of voltage, the display state is maintained.

In the same manner, in displaying image data for the “i”th line (1≦i≦m),in response to a timing signal (column direction), the image data forthe “i”th line is stored in the line buffer 71. On completion of thestorage, the image data for the “i”th line are read out simultaneouslyfor the respective columns. The eight-bit image data are converted intoanalog image signals by the D/A converters 72. The driving buffers 74amplify the analog image signals outputted from the D/A converters 72,and the amplified signals are sent to the electrode columns C1, C2 . . .Cn.

In the meantime, the timing controller 70, at the timing of displayingthe image data for the “i”th line, sends a command to the decoder 75 toturn on only a switching circuit 76-i and to turn off the otherswitching circuits. Accordingly, the output from the DC/DC converter 73is sent to only the electrode row Ri. Thereby, only the “i”th linecorresponding to the electrode row Ri comes to a display state, and evenafter stoppage of the application of voltage, the display state ismaintained.

Such a driving process is repeated to display a whole picture, and if acommand of displaying a new picture is dispatched, the same process isrepeated from the first line to the last line to display the picture.

As described above, the data electrode driving circuit 22 comprises theline buffer 71, the D/A converters 72, and the driving buffers 74, andthe scan electrode driving circuit 21 comprises the timing controller70, the DC/DC converter 73, the decoder 75 and the switching circuits76-1 through 76-m. The timing controller 70 and the DC/DC converter 73may be included in the data electrode driving circuit 22. Further, it isnot difficult to structure these circuits 21 and 22 in one chip. Sincethe liquid crystal display 10 is a full-color display, three channels ofsuch driving circuits 21 and 22 (for R, G and B) are necessary.Actually, therefore, three sets of the data electrode driving circuit22, the decoder 75, the switching circuits 76-1 through 76-m areprovided, and these are controlled by the single timing controller 70.

Incidentally, since such a memory card is an exchangeable storage mediumtoward electronic information equipment, there are two types withrespect to its driving section: a driving section internally installedtype which has a driving section inside the memory card itself; and adriving section externally installed type which has part of its drivingsection which is also used for electronic information equipmentinstalled outside the memory card.

Driving Section Internally Installed Type

The driving section internally installed type means that the wholedriving circuit for the liquid crystal display 10 is installed in thememory card. Accordingly, by receiving only RGB data from outside, theliquid crystal display 10 can make a complete picture thereon. Thisrequires easy control. In a case of using an interface for general usesuch as the PCMCIA standard as described above, this type must be used.

Driving Section Externally Installed Type

The driving section externally installed type means that part of thedriving circuit for the liquid crystal display 10 is installed in adevice such as a digital camera, a personal computer or the like inwhich the memory card is to be inserted when it is used. Accordingly,this decreases the size and the cost of the memory card.

In the driving circuit shown by FIG. 13, it is preferred to install thepart which is enclosed by a double line in the memory card. The otherpart can be installed in a digital camera, a personal computer or thelike. By installing at least the part enclosed by the double line in thememory card, even if a larger number of electrodes become necessary withan increase in number of the display pixels, the number of pins of theconnector may not be increased so much.

Digital Camera which can Employ Memory Card with Memory-Effective LiquidCrystal

A digital camera which can employ the above-described memory card withmemory-effective liquid crystal as a storage medium of photo data.

Since the memory card has a display section, it is possible to displayany information about the digital camera on the display section of thememory card. First, however, a type which further has a display sectionfor the digital camera besides the display section of the memory card isdescribed.

Display Section Separate Type Structure of Digital Camera

In FIGS. 14 through 17, a digital camera 100 comprises a camera body 102and an image pick-up unit 103. The image pick-up unit 103 is attached tothe right side of the camera body 102 viewed from the front side and isdetachable from the camera body 102.

The image pick-up unit 103 has a conventional CCD 303 which functions asa color area sensor (see FIG. 18) at a suitable place in the rear sideof a zoom lens 301 with a macro function. As in a camera using a silversalt film, a light-adjusting circuit 304 with a light-adjusting sensor305 which receives reflection of flash light from an object, a distancesensor 306 which measures the distance to an object and an opticalfinder 307 are provided at suitable places inside the image pick-up unit103.

In the image pick-up unit 103, also, a zoom motor M1 (see FIG. 18),which moves the zoom lens 301 for a change in zoom ratio and formovement between a retreating position and a photography position, and amotor M2, which carries out focusing, are provided.

On the front side of the camera body 102, a grip 104, a built-in flash105 and an IRDA port 106 which performs infrared communication betweenthe digital camera 100 and an external device (for example, anotherdigital camera, a personal computer or the like) are provided. On theupper side of the camera body 102, a shutter button 109 is provided.

As FIG. 15 shows, on the rear side of the camera body 102, an LCDsection 110, which makes a monitor display (corresponding to aviewfinder) and reproduces a stored image, is provided in the center.Below the LCD section 110, a key switch group 111 for control of thedigital camera 100 and a power switch 112 are provided. On the left sideof the power switch 112, an LED 113, which is lit when the power switch112 is on, and an LED 114, which indicates the middle of an access tothe memory card, are provided.

Further, on the rear side of the camera body 102, aphotography/reproduction mode setting switch 120 for switching between aphotography mode and a reproduction mode is provided. The photographymode is to take a photograph, and the reproduction mode is to reproducean image stored in the memory card on the LCD section 110. Thephotography/reproduction mode setting switch 120 is a two-contact slideswitch. For example, by sliding the switch 120 downward, thereproduction mode is set, and by sliding the switch 120 upward, thephotography mode is set.

On the rear side of the camera body 102, in the right side, a four-throwswitch is provided. By pressing buttons 121 and 122 of the four-throwswitch, the zoom motor M1 is driven for zooming, and by pressing buttons123 and 124 of the four-throw switch, exposure adjustment is performed.

As shown in FIG. 15, on the rear side of the image pick-up unit 103, anLCD button 311 and a macro button 312 are provided. Every time the LCDbutton 311 is pressed, the LCD section 110 is turned on or off. Forexample, in taking photographs while using only the optical finder 307,the LCD section 110 shall be turned off to save energy. By pressing themacro button 312, the focus motor M2 is driven to permit macro imagingof the lens 301.

As FIG. 16 shows, on a side of the digital camera 100, a DC inputterminal 308 and a video output terminal 309 are provided. The videooutput terminal 309 is to output an image displayed on the LCD section110 to an external video monitor.

As FIG. 17 shows, on the bottom of the camera body 120, a battery room131 and a card room 132 for a memory card are provided, and these roomsare closed by a clamshell type cover 130. This digital camera 100requires four AA batteries which are serially connected as its drivingsource 135. Further, on the bottom side, a disconnecting lever 136, todisconnect the image pick-up unit 103 and the camera body 102 which areconnected by a connector and a hook from each other, is provided.

Control Circuit

Next, referring to FIG. 18, a control circuit of the image pick-up unit103 is described.

The CCD 303 performs photoelectric conversion of an optical image of anobject which has been obtained by the macrozoom lens 301 to output colorimage signals of R, G and B (signals each of which is composed of rowsof pixel data). A timing generator 314 generates various timing pulsesfor control of the CCD 303.

In the image pick-up unit 103, since the stop is fixed, the exposureadjustment is performed by adjusting the exposure of the CCD 303 andmore specifically by adjusting the charging time of the CCD 303corresponding to the shutter speed. When it is impossible to set anappropriate shutter speed because the luminance of the object is low,inappropriate exposure because of lack of exposure is corrected byadjusting the levels of the image signals outputted from the CCD 303.Thus, when the luminance is low, both shutter speed and gain areadjusted for exposure control. The adjustment of the levels of the imagesignals is carried out by gain control in an AGC circuit in a signalprocessing circuit 313.

The timing generator 314 generates a driving control signal of the CCD303 based on a reference clock sent from a timing control circuit 202.For example, the timing generator 314 generates clock signals such as atiming signal for a start/stop of integration (a start/stop ofexposure), a pixel data reading control signal (a horizontal synchronoussignal, a vertical synchronous signal, a transmission signal or thelike), etc. and outputs these signals to the CCD 303.

The signal processing circuit 313 performs specified analog signalprocessing toward each image signal (analog signal) outputted from theCCD 303. This signal processing circuit 313 has a CDS (correlated doublesampling) circuit and an AGC (auto gain control) circuit. In the CDScircuit, the noise of the image signals is reduced, and by controllingthe gain in the AGC circuit, the levels of the image signals areadjusted.

The light-adjusting circuit 304 controls the quantity of light emittedfrom the built-in flash 105 to emit a quantity of light which ispredetermined by a central control section 211. In flash photography,simultaneously with a start of exposure, the sensor 305 starts receivingreflected light from an object irradiated by flash light, and when thequantity of light received by the sensor 305 reaches a specified value,a lighting stop signal is outputted from the demodulating circuit 304. Aflash driving circuit 216 stops light emission of the built-in flash 105in response to the lighting stop signal. Thus, the quantity of lightemitted from the flash 105 is controlled.

The image pick-up unit 103 and the camera body 102 are electricallyconnected to each other by seven connector groups 334 a, 334 b, 334 c,334 d, 334 e, 334 f and 334 g which are provided on the fitting surface334 of the image pick-up unit 103 and by seven connector groups 234 a,234 b, 234 c, 234 d, 234 e, 234 f and 234 g which are provided on theconnecting surface 234 of the camera body 102.

Next, a control circuit of the camera body 102 is described.

In the camera body 102, an A/D converter 205 converts each signal for apixel of the image signals into a ten-bit digital signal. Based on anA/D conversion clock sent from the timing control circuit 202, eachpixel signal (analog signal) is converted into a 10-bit digital signal.

The timing control circuit 202 generates a reference clock and clocks tobe outputted to the timing generator 314 and the A/D converter 205 andis controlled by the central control section 211.

A black level adjusting circuit 206 adjusts the black level of the A/Dconverted pixel signal (hereinafter referred to as pixel data) to aspecified black level. A WB circuit 207 changes the levels of the pixeldata of the respective colors R, G and B so that the white balance willbe appropriate after γ correction. The WB circuit 207 uses a levelconversion table sent from the central control section 211 in changingthe levels of the RGB color pixel data. The conversion coefficients(inclinations of characteristics) for the respective colors in the levelconversion table are determined by the central control section 211 forevery photography.

A γ correcting circuit 208 is to correct the γ characteristic of pixeldata. An image memory 209 is to be stored with pixel data outputted fromthe γ correcting circuit 208. The image memory 209 has a storagecapacity for one-frame data. More specifically, if the CCD 303 haspixels arranged in n columns and in m rows, the image memory 209 has acapacity of pixel data for n×m pixels, and data for the respectivepixels are stored in respective places in the memory 209.

A VRAM 210 is a buffer memory for image data to be reproduced on the LCDsection 110. This VRAM 210 has a storage capacity of image datacorresponding to the number of pixels of the LCD section 110.

During a stand-by for photography, images are picked up by the imagepick-up unit 103 at regular time intervals. Pixel data of each picked-upimages are subjected to specified signal processing by the A/D converter205 through the γ correcting circuit 208 and stored in the image memory209. Simultaneously, the data are transmitted to the VRAM 210 via thecentral control section 211 to be displayed on the LCD section 110(display of a live view image). From the image displayed on the LCDsection 110, the user can obtain a vision of the object. In thereproduction mode, image data read out from the memory card aresubjected to specified signal processing at the central control section211, and the data are transmitted to the VRAM 210 to be displayed on theLCD section 110.

A card I/F 212 is an interface for recording and reading of image datato and from the memory card.

The flash driving circuit 216 is to control light emission of thebuilt-in flash 105. This driving circuit 216 controls the necessity oflight emission of the built-in flash 105, the quantity of light to beemitted, the timing of light emission, etc. based on a control signalsent from the central control section 211, and the quantity of emittedlight is controlled specifically based on the light emission stop signalsent from the light-adjusting circuit 304. An RTC 219 is a clock circuitwhich manages the date and time of photography and is driven by anotherelectric power source (not shown). An operation section 250 means theabove-described various keys, switches and buttons.

Incidentally, the shutter button 109 is, like one employed in a camerausing a silver-salt film, a two-level switch which has a half-pressedstate S1 and a full-pressed state S2. During a stand-by, when theshutter button 109 is pressed half-way (S1), distance informationdetected by the distance sensor 306 is inputted to the central controlsection 211. The central control section 211 drives the AF motor M2based on this distance information to move the zoom lens 301 forfocusing.

The central control section 211 is a CPU to organize photographyoperation of the digital camera 100 by integrally controlling drives ofthe members in the image pick-up unit 103 and in the camera body 102.The central control section 211 is connected to the peripheral circuitsby address buses, data buses and control buses. In FIG. 18, the arrowsare used for convenience to show the flows of signals and image data.Actually, image data are sent to the respective circuits via the centralcontrol circuit 211, and therefore, the central control section 211 isprovided with a ROM (not shown) to be stored with a work memory and aprogram.

Also, the central control section 211 has a luminance judging sectionand a shutter speed setting section to determine the exposure value(shutter speed). The luminance judging section judges the brightness ofan object using images picked up by the CCD 303 at intervals of 1/30second during a stand by for photography. In other words, the luminancejudging section judges the brightness of an object using image datawhich are renewably stored in the image memory 209. The shutter speedsetting section sets a shutter speed (integrated time of the CCD 303)based on the judgment of the luminance judging section.

Further, the central control section 211 has a filter section whichperforms a filtering treatment for recording of a photographed image, animage recording section which produces a thumbnail image and acompressed image and an image reproducing section which reproduces animage to be displayed on the LCD section 110 from data stored in thememory card.

The filter section adjusts the high-frequency component of an image tobe recorded by a digital filter so as to correct the picture qualitywith respect to the outline.

The image recording section reads pixel data from the image memory 209and produces a thumbnail image and a compressed image to be stored inthe memory card. The image recording section reads data of every eightpixels in the horizontal direction and in the vertical direction whilescanning the image memory 209 in a raster scanning direction andtransmits the pixel data to the memory card in order, whereby athumbnail image is produced and recorded in the memory card.

The image recording section reads all the pixel data of one image fromthe image memory 209 and performs two-dimensional DCT conversion and acompression treatment based on a JPEG method, such as a Huffman encodingmethod, toward the pixel data to produce data for a compressed image.Then, the compressed image data are recorded in an image area of thememory card.

In the photography mode, when the shutter button 109 is pressed for acommand of photography, the central control section 211 processes theimage which has been photographed and taken in the image memory 209 to athumbnail image and a compressed image by applying a compressiontreatment based on the JPEG method at a ratio set by a compression ratiosetting switch. Then, the compressed image is stored in the memory cardwith tag information about the photographed image (frame number,exposure value, shutter speed, compression ratio, date of photography,on/off of the flash, scene information, result of judgment of the image,etc.).

In each frame of the digital camera 100, tag data, high-resolution imagedata compressed based on the JPEG method (1600×1200 pixels) andthumbnail image data (80×60 pixels) are recorded. The volume of datarecorded in one frame is approximately 1 MB.

When the photography/reproduction mode setting switch 120 is set to thereproduction mode, image data in the frame of the highest number areread out of the image memory, and the data are expanded by the imagereproducing section. Then, the expanded data are transmitted to the VRAM210, whereby the image in the frame of the highest number, that is, thelatest photographed image is displayed on the LCD section 110. Byoperating an UP switch 111 a, an image in the higher frame number isdisplayed, and by operating a DOWN switch 111 b, an image in the lowerframe number is displayed.

Display Sequence of Liquid Crystal Display

An exemplary sequence of displaying data on the liquid crystal display10 of a display section separate type digital camera is described.

(1) Renewal of Image on Card

The memory card 56 shown by FIG. 9, which is of a memory section/displaysection separate type and of a driving section internally installedtype, is shown by FIGS. 19 and 20 again and is described as an exemplarymemory card fitted in the digital camera 100. As mentioned above, thememory card 56 is compatible with conventional ordinary memory cards.The liquid crystal display 10 comprises 300 pixels in each row and 400pixels in each column, and the electrodes 15 and 16 are formed inaccordance with the arrangement of the pixels.

Such memory cards 56 in a non-display state are distributed to users(see FIG. 19). In the control procedure described below, after a userfits the memory card 56 in the digital camera 100, a thumbnail pictureon the liquid crystal display 10 is renewed every time a photograph istaken.

FIG. 21 is a flowchart of the control procedure. When the digital camera100 is turned on, first at step S10, the presence or absence of a memorycard in the camera 100 is judged. If there is no card, a warning isdisplayed at step S11. If there is a card, it is judged at step S12whether or not the card is a memory card with memory-effective liquidcrystal. This judgment is made from the attribute (data stored in aspecified address) of the card. If there is no card in the camera 100 orif there is a conventional memory card in the camera 100 (“NO” at stepS12), ordinary processes of a conventional digital camera are carriedout at step S13. When a memory card with memory-effective liquid crystalis fitted in the digital camera, it is judged at step S14 whether or nota format for a digital camera is necessary.

If a format is necessary, a format process is performed at step S15. Atstep S15, a format process is started after the user's confirmation, andduring the format process, the central control section 211 performswriting on the liquid crystal display 10 via the card I/F 212. Aftercompletion of the format process, a framework 80 for thumbnail images,the number of photographed frames 82 and the remaining capacity of thecard 83 are displayed on the liquid crystal display 10. A thumbnailimage of one frame is of a size of 80×60 pixels and a space for displayof information must be set in the periphery. Accordingly, thumbnailimages of 16 frames can be displayed. Further, depending on the imagesize of the digital camera and the capacity of the memory card, morethan 16 photographs can be taken. In this case, thumbnail images of allthe frames are displayed by reducing the size of each image, or onlythumbnail images of the latest used 16 frames are displayed.

If a format process is unnecessary (“NO” at step S14), a flag is checkedat step S16 to judge whether or not the digital camera 100 is in a stateright after the memory card with memory-effective liquid crystal hasbeen fitted therein. This flag is 0 while there is no memory card in thedigital camera 100. When a memory card is fitted in the digital camera100, the flag is set to 1. Accordingly, by checking the state of thisflag, the presence or absence of a memory card in the digital camera 100can be judged.

Right after fitting of a memory card in the digital camera 100, there isa possibility that the picture on the liquid crystal display may be outof order, and therefore, although photography has not been performedyet, the picture on the liquid crystal display is renewed at step S17.More specifically, thumbnail images are read out from the memory cardand displayed. Thereafter, the liquid crystal display is controlled atstep S18.

Referring to FIG. 22, a liquid crystal display control procedureperformed at step S18 is described. First at step S21, the mode of thecamera is judged. If the photography mode is set, processes at steps S22through S24 are performed. It is judged at step S22 whether or not theshutter button 109 has been fully pressed, that is, has come to thestate S2. When the shutter button 109 has been fully pressed, at stepS23, image data processing of a photographed image is performed, and thedata are recorded into a flash memory of the memory card 56. At stepS24, the thumbnail picture on the liquid crystal display 10 is renewed.More specifically, as FIG. 23 shows, thumbnail images 85 and framenumbers 81 of photographed images are displayed in the respectivedisplay sections for the frames. Simultaneously, the number of usedframes 82 and the remaining capacity 83 of the memory card 56 arerenewed. Then, other processes in the photography mode are carried outat step S25, and the program goes to step S33.

In the liquid crystal display 10, as described above, the data electrodedriving circuit 22 drives the data electrodes which extend in the columndirection, and therefore, data are written row by row. Accordingly,addition of a thumbnail image is made in the column direction as shownby arrow “Y” in FIG. 23. If a thumbnail image is added in the rowdirection (perpendicular to the direction of arrow “Y”), for example,when a thumbnail image of the second frame is to be added, the thumbnailimage of the first frame must be written again, which requires more timefor renewal.

If the data electrode driving circuit 22 of the liquid crystal display10 drives the data electrodes which extend in the row direction,addition of a thumbnail image shall be made in the row direction. Inshort, addition of a thumbnail image shall be made in a directionparallel to the extending direction of the data electrodes driven by thedata electrode driving circuit 22.

In the reproduction mode, in the LCD section 110 of the camera 100,simultaneous display of all the photographed images, format of thememory card, and deletion of a specified image are possible. FIG. 24shows main pictures changeably displayed on the LCD section 110 in thereproduction mode. Right after a mode change from the photography modeto the reproduction mode, the photographed image of the highest framenumber is displayed, and then, by operating the operation key 111, thepicture is changed to a menu selection picture D1.

On the picture D1, four modes shown in FIG. 24 are available, and thesemodes can be selected cyclicly by pressing the buttons 123 and 124 ofthe four-throw switch. When an execute key 111 d is pressed with “memorycard format” selected in the picture D1, a picture D2, which shows thata format process is being performed, appears. On completion of theformat of the memory card, the display returns to the picture D1.

When the execution key 111 d is pressed with “photo data deletion”selected in the picture D1, a picture D3, which shows all thephotographed images, appears. In this state, by operating the four-throwkey 121 through 124, a specified image can be selected, and the selectedimage is enclosed by a frame 90. Then, by pressing the key 111 d, thedata of the selected image are deleted. When a return key 111 f ispressed, the display returns to the picture D1.

Referring to FIG. 22 again, this operation is described. It is judged atstep S26 whether or not format of the memory card has been commanded.When the format is designated and commanded, a format process of thememory card is performed at step S27. Next, the picture on the liquidcrystal display 10 is renewed at step S28, and more specifically, allthe thumbnail images are erased.

When deletion of a photographed image is commanded (“YES” at step S29),data of the designated frame are deleted at step S30, and the thumbnailpicture on the display 10 is renewed at step S31. More specifically, ifdata of the “n”th frame are deleted, image data of the “n+1”th frame isrestored as image data of the “n”th frame, and the thumbnail image ofthis frame is displayed in the section for the “n”th frame. Theseprocesses are performed to all the image data of the “n+1”th andsubsequent frames. At step S32, other processes in the reproduction modeare carried out, and the program goes to step S33.

At steps S33 through S35, electric power is shut off. It is judged atstep S33 whether or not a command of power off has been issued byoperation of the power switch 112. If power off has not been commanded,the program returns to the main routine. If power off has beencommanded, completion of renewal of the thumbnail picture is waited atstep S34, and a power-off process is performed at step S35. Thereby,there is no trouble that power may be turned off in the middle ofrenewal of the thumbnail picture.

Display Section Commonly Used Type

Since the memory card according to the present invention has a liquidcrystal display section, it is possible to display not only the contentof the memory card but also information about a digital camera on thedisplay section. In the following, a digital camera 100′ which commonlyuses a display section of a memory card is described. FIGS. 14 and 16are also a front view and a side view of this camera 100′. FIGS. 25 and26 are a rear view and a bottom view of the digital camera 100′,respectively. The same members are denoted by the same reference symbolsas shown in FIGS. 14 through 17, and repetition of descriptions of thesemembers is omitted. Although a case of using the memory card shown byFIG. 9 will be described, needless to say, memory cards of other typescan be used.

Referring to FIGS. 25 and 26, on a display support 140 provided on therear side of the camera body 102, a card slot 141 and a connector 142for the memory card 56 are provided. The memory card 56 is inserted inthe camera 100′ through the lower side of the display support 140. Onthe rear side of the display support 140, in a place facing the liquidcrystal display 10 of the memory card 56, a window 143 is formed.Thereby, when the memory card 56 is inserted, the screen of the liquidcrystal display 10 can be seen, and in this state, the liquid crystaldisplay 10 can be also used as a display section of the camera 100′.

Further, the digital camera 100′ has, in the camera body 102, an LCDsection 110 using conventional TFT liquid crystal which emits light froma back light. Because the renewal speed of the liquid crystal display 10is relatively low, the LCD section 110 is exclusively used to display amotion picture. By pressing the LCD button 311, the LCD section 110 canbe turned on and off. If low-speed renewal of a motion picture ispermissible, the LCD section 110 is not always necessary. If the LCDsection 110 is not provided, the LCD button 311 is unnecessary.

An operation sequence in a case of using the liquid crystal display 10of the memory card 56 as a display section of a camera is described.

(1) Case of not Providing LCD Section 110

In this case, from the control circuit shown by FIG. 18, the VRAM 210,the LCD section 110 and the back light 160 are omitted. The omission ofthe back light 160 especially reduces the consumption of electric power,which prolongs the lives of the batteries.

Processes after power-on are performed in a similar way to the flowchartshown by FIG. 21. However, since a display section is not provided, thewarning display of indicating no card at step S11 is made by flickeringof the LED 114. After format, the display section of the card is in astate shown by FIG. 27, where the framework 80 for thumbnail images (seeFIG. 20) are not displayed. In this display section commonly used type,there are various kinds of information to be displayed on the liquidcrystal display 10 as well as thumbnail images, and it is not desirableto display the thumbnail framework 80 after every format.

The control of the liquid crystal display 10 at step S18 is carried outfollowing the flowcharts shown by FIGS. 28 and 29. First at step S51,the state of the mode switch 120 is judged. In the photography mode,necessary processes are performed at step S52, and in the reproductionmode, necessary processes are performed at step S53. Processes to shutoff the power are performed at steps S54 through S56 in the same way assteps S33 through S35.

Next referring to FIG. 29, the processes in the photography modeperformed at step S52 is described. First at step S61, a photographymode picture shown by FIG. 30 appears on the liquid crystal display 10.In FIG. 30, the portion enclosed by the dotted line shows the memorycard 56 inserted in the camera body 102. The numeral 82 denotes thenumber of used frames, and the numeral 83 denotes the remaining capacityof the memory card 56. The numeral 87 denotes a status line wherevarious warnings such as a lack of illuminance are displayed. Thenumerals 88, 89 and 90 denote labels which show the states of the camera100′ with respect to the items selected by keys which are right underthe labels. By pressing a key 111 d right under the label 88, any ofstill photography, continuous shooting and interval shooting can beselected. By pressing a key 111 e right under the label 89, the mode ofthe flash 105 can be changed. By pressing a key 111 f right under thelabel 90, the size of a live view display area can be changed.

The live view display area is changeable between a small size 91 and alarge size 92. When the display area is small, the number of pixels usedfor a display, and it is not necessary to rewrite a large area, whichshortens the time for renewal of the image on the liquid crystal displayis small 10. On the other hand, when the display area is large, althoughit takes a longer time for renewal, the details of the object can berecognized because the number of used pixels is large. In this way, bychanging the size of the live view display area depending on thepurpose, both the efficiency and the visibility can be satisfied.

Referring back to FIG. 29, it is judged at step S62 whether or not theshutter button 109 is in the half-pressed state S1. If the button 109 isnot in the state S1, it is judged at step S63 whether or not the liquidcrystal display 10 is in the middle of image writing. If not, it isjudged at step S71 whether or not any other key is operated. If there isno operation of keys, the central control section 211 commands supply ofelectric power to the image pick-up unit 103 at step S73 and commandspick-up of a live view image at step S74. Thereafter, image data arestored in the image memory 209 at step S75, and on completion of thestorage of image data, the power supply to the image pick-up unit 103 isshut off at step S76. Next, at step S77, in accordance with the imagedata stored in the image memory 209, writing of a live view image on theliquid crystal display 10 is started. Then, the program returns to stepS62.

After completion of the writing, as long as operation of no keys otherthan the shutter button 109 is recognized (“NO” at step S71), pick-up ofa next live view image is performed at step S74. Thus, the completion ofrenewal of the image on the liquid crystal display 10 is used as atrigger to command the image pick-up unit 103 to pick up a live viewimage. Thereby, during writing of a live view image on the liquidcrystal display 10, the CCD 303 can be turned off, which promotes savingof electric power. Further, the trigger to command pick-up of a nextlive view image does not have to be the completion of image writingwhich is judged at step S63 and may be a time a little earlier than thecompletion of image writing.

In this control procedure, when “NO” at step S63, the program goes tostep S71. This means that during image writing on the liquid crystaldisplay 10, operation of any key is not inputted. With this arrangement,there is no possibility that whenever operation of any key is receivedin the middle of image writing, the image writing is performed againfrom the beginning, that is, it never takes so long a time for renewalof the image on the liquid crystal display 10, and the efficiency ofthis camera 100′ is highly improved.

When the shutter button 109 is in the half-pressed state S1 (“YES” atstep S62), the image pick-up unit 103 is turned on at step S64, and anAF process and an AE process are performed at step S65. Thereafter, whenit is judged at step S66 that the shutter button 109 comes to thefull-pressed state S2, data of an image photographed by the CCD 303 aretaken in at step S68, and the image data are stored in the flash memoryof the memory card 56 at step S69. Then, the image pick-up unit 103 isturned off at step S70, and the program goes to step S71.

On the other hand, if the shutter button 109 does not come to the stateS2 (“NO” at step S66), it is judged at step S67 whether or not theshutter button 109 is in the state S1. If the shutter button 109 is inthe state S1, the program returns to step S65. If the shutter button 109is not in the state S1, the power supply to the image pick-up unit 103is shut off at step S70, and the program goes to step S71.

Although operations of keys are not received during image writing on theliquid crystal display 10, only when the shutter button 109 is in thestate S1, operations of keys are received. Therefore, the user nevermisses a shutter chance.

When an operation of any other key is recognized at step S71, a processin compliance of the operation of the key is performed at step S72. Forexample, when a mode change to the reproduction mode is commanded, areproduction mode process, which will be described below, is performed.

Now referring to FIG. 31, a control procedure in the reproduction modeis described. First at step S81, it is judged whether or not a modechange from the photography mode has been made. If the change has beenmade, a timer T1, which is used to judge whether the camera 100′ has notbeen operated for a specified time, is reset at step S82. Then, at stepsS83 through S85, the picture on the liquid crystal display 10 is changedto one for the reproduction mode.

Specifically, at step S83, image data of the highest frame number isread out of the flash memory of the memory card 56, and the image isdisplayed at step S84. Here, the picture shown by FIG. 32 is displayed.In FIG. 32, the same reference symbols as used in FIG. 30 show the sameitems. What are newly displayed are a label 94 for deletion and a label95 for one-frame display. The key 111 d right under this label 94functions as a delete key. The key 111 e right under the label 95functions as a one-frame display/thumbnail display switching key. In theportion denoted by the numeral 87, the status of the camera 100′ isdisplayed; however, the file name of the displayed image, the date andtime of photography, etc. may be also displayed in the portion 87 ifnecessary. The numerals 91 and 92 denote areas where a photographedimage can be displayed. By pressing the key 111 f right under the label90, the size of the display area can be changed as in the photographymode.

Thus, because the content of the display for the photography mode andthe content of the display for the reproduction mode overlap (the numberof used frames 82, the remaining capacity 83, etc.), at the time of amode change, the picture on the liquid crystal display 10 does not haveto be wholly changed, which saves time for renewal.

Referring back to FIG. 31, at step S85, the information of the imagedisplayed on the liquid crystal display 10 is temporarily saved in thework memory of the central control section 211. The reason will bedescribed later. The format for the temporary saving is as follows:

codes to be displayed on the status line: file name, date and time ofphotography, etc.

frame number: frame number currently displayed

states of the keys: the content of 94, 95 and 90

Next, it is judged at step S86 whether or not a change of displayedframe has been commanded, and the timer T1 is reset at step S87. Theframe change is made in the following way: when the button 121 of thefour-throw switch is pressed, the liquid crystal display 10 takes inimage data of the frame of one lower number and displays the image; andwhen the button 122 is pressed, the liquid crystal display 10 takes inimage data of the frame of one higher number and displays the image. Inshort, at steps S88 and S89, image data are taken into the liquidcrystal display 10, and the picture on the display 10 is renewed. Atstep S90, the information of the displayed image is saved in the workmemory.

Next, it is judged at step S91 whether or not a change of the displayarea size has been commanded. When the change is commanded, the timer T1is reset at step S92. Then, image data of the frame are taken into theliquid crystal display 10 again at step S93, and at step S94, the imageis displayed in the area of the designated size. Subsequently, at stepS95, the information of the displayed image is saved in the work memory.

Further, if an operation of any other key is recognized at step S96, thetimer T1 is reset at step S97, and a process in compliance with theoperation of the key is performed. If necessary, the picture on theliquid crystal display 10 is renewed, and the information is saved.Then, the program returns to the main routine.

On the other hand, if “NO” at step S96, that is, when no keys areoperated, the timer T1 counts up at step S99. After it is judged at stepS100 from the count-up of the timer T1 that the camera 100′ has not beenoperated for a specified time (for example, five minutes), theinformation of the currently displayed image is read out of the workmemory at step S101. Then, the image indicated by the information isdisplayed again on the liquid crystal display 10 at step S102, and thetimer T1 is reset at step S103.

The picture on the liquid crystal display 10 is renewed at step S102because of the following reason. Cholesteric liquid crystal used in thisembodiment has an advantage of not consuming electric power whilemaintaining a display thereon. Accordingly, while no operation is madeto the liquid crystal display 10, the same picture is continuouslydisplayed. If any external stress is applied to the display 10 duringthe time, the state of the liquid crystal may partly change and maycause deformation of the displayed picture. In order to avoid thistrouble, at regular time intervals, for example, every five minutes, thepicture on the display 10 is renewed.

Operations to be recognized at steps S96 and S100 includes a change fromthe reproduction mode to the photography mode. The mode change isperformed at step S98, and in this time, the work memory is cleared.

(2) Case of Providing Display Section 110

In this case, in the photography mode, a live view image is displayed onthe display section 110 which employs conventional TFT liquid crystaland a back light. In the reproduction mode, control is carried outfollowing the procedure shown by FIG. 31. The control procedure in thephotography mode is shown by FIG. 33.

When a mode change from the reproduction mode to the photography mode ismade, first at step S111, the picture on the liquid crystal display 10is renewed, and a thumbnail picture is displayed thereon as shown byFIG. 34. Like the thumbnail picture shown by FIG. 23, every time aphotograph is taken, a thumbnail image of the photographed image isadded to this thumbnail picture. In FIG. 34, the parts with the samefunctions as those in FIGS. 23 and 30 are denoted by the same referencesymbols, and description of these parts are omitted.

Since in the photography mode, a live view image is displayed on thedisplay section 110 which is TFT liquid crystal with a back light, theimage pick-up unit 103 is turned on at step S112, and live view imagesare taken in and displayed at regular time intervals. The image pick-upis described in more detail. It is judged at step S113 whether or notthe shutter button 109 is in the half-pressed state S1. If the shutterbutton 109 is not in the state S1 and if operation of any other key (forexample, a mode change to the reproduction mode) is recognized at stepS119, a process in compliance with the operation of the key is performedat step S120. Then, the program returns to the main routine.

If no other keys are operated (“NO” at step S119), a command for pick-upof a live view image is issued at step S121. Data of the live view imageare taken into the image memory 209 at step S122, and the image isdisplayed on the LCD section 110 at step S123. Then, the program returnsto step S113.

When “YES” at step S113, that is, when the shutter button 109 is in thestate S1, an AF process and an AE process are performed at step S114.Thereafter, when the shutter button 109 is judged to come to thefull-pressed state S2 at step S115, data of the photographed image aretaken in and processed at step S116, and the image data are stored inthe flash memory of the memory card 56. Next, a thumbnail image of thephotographed image is displayed on the liquid crystal display 10 at stepS118.

Error Management

In using a memory card with memory-effective liquid crystal, as in usinga conventional memory card, there is a possibility that recording andreading of data to and from the flash memory may become impossible byany reason. The following table shows probable errors and the causes.

Because the memory card according to this embodiment has a liquidcrystal display with a memory effect, it is possible to display an errorcode on the display to inform the user of the kind of the error.Further, it is possible to display the cause and the measures as well asthe error code.

TABLE 1 Error Code Kind of Error Cause 1 error of data recording todamage on flash memory memory card 1 2 Error of data recording to overcapacity memory card 2 3 error of data reading from damage on flashmemory memory card 1 4 error of data reading from theoretical disordermade in memory card 2 data recording 5 Non-operational central controlsection beyond control, removal of memory card during an access

In order to manage these errors, as FIG. 35 shows, the timing controller70 of the memory card according to this embodiment comprises a timingsignal generating section 701, an error detecting section 702, and errordisplay data 703, a capacitor 704 and a memory managing section 705.

Error of Data Recording to Memory Card 1

The timing signal generating section 701 performs display on the liquidcrystal display 10 and data recording to the flash memory controlled bythe central control section 211. When data are recorded in the flashmemory, the central control section 211 checks whether or not specifieddata are correctly recorded to the flash memory. If the central controlsection 211 recognizes disorder during the check, the central controlsection 211 sends information of an occurrence of the recording error 1to the error detecting section 702 via the timing signal generatingsection 701. In response, the error detecting section 702 selects apiece of display data corresponding to the error code 1 from the errordisplay data 703 and sends the display data to the timing signalgenerating section 701. Then, the display data are displayed in anappropriate place on the liquid crystal display 10.

Error of Data Recording to Memory Card 2

The memory managing section 705 has a memory which is stored with dataabout the remaining capacity and the number of used frames. The centralcontrol section 211 records 1024 bits of data at a time when recordingdata to the flash memory. When the remaining capacity of the flashmemory becomes smaller than 1024 bits, the central control section 211sends information of an occurrence of the recording error 2 to the errordetecting section 702 via the timing signal generating section 701. Inresponse, the error detecting section selects a piece of display datacorresponding to the error code 2 from the error display data 703 andsends the display data to the timing signal producing section 701. Then,the data are displayed in an appropriate place on the liquid crystaldisplay 10.

Error of Data Reading from Memory Card 1

For data reading from the flash memory, the central control section 211designates the address in the flash memory from which data are to beread out, and data are read out in synchronization with a reading timingsignal outputted from the timing signal generating section 701. At thistime, if data reading from the designated address is impossible, theerror detecting section 702 selects a piece of display datacorresponding to the error code 3 from the error display data 703 andsends the display data to the timing signal generating section 701.Then, the data are displayed in an appropriate place on the liquidcrystal display 10.

Error of Data Reading from Memory Card 2

As mentioned above, for data reading from the flash memory, the centralcontrol section 211 designates the address in the flash memory fromwhich data are to be read out, and data are read out in synchronizationwith the reading timing signal outputted from the timing signalgenerating section 701. In this time, if any disorder of data isrecognized from the check sum, it can be regarded that any disorderoccurred at the time of data recording. Accordingly, the error detectingsection 702 selects a piece of display data corresponding the error code4 from the error display data 703 and sends the display data to thetiming generating section 701. Then, the data are displayed in anappropriate place on the liquid crystal display 10.

Non-Operational

The above-described error check processes are installed in the internalroutine of the central control section 211. If the central controlsection 211 itself becomes beyond control and stops (the system may beso designed to shut the power off in such a case for protection of thesystem), the error check processes are not operative. The same thinghappens when the memory card is taken out of the camera during anaccess.

In order to manage such a case, the memory card has a capacitor 704 witha capacity of approximately 300 μF. If the central control section 211becomes beyond control, an error display is made by use of electricitystored in the capacitor 704.

The error detecting section 702 monitors signals exchanged between thecentral control section 211 and the timing signal producing section 701via a control bus. If the timing clock stops or if a memory accesssignal stops suddenly whereas the timing clock works, it is judged thatthe central control section 211 becomes beyond control or that thememory card is taken out during an access. Accordingly, the errordetecting section 702 selects a piece of display data corresponding tothe error code 5 from the error display data and sends the display datato the timing signal generating section 701. Then, the data aredisplayed in an appropriate place on the liquid crystal display 10.

Thus, because the liquid crystal display 10 has a memory effect, anerror display can be made even when the power is off. This brings aneffect that the system can be protected while an error is managed.

Control Procedure Including Automatic Power-Off Process

The above-described digital cameras 100 and 100′ are controlled not toaccept a power-off command during image writing on the liquid crystaldisplay 10 (see steps S32 through S35 in FIG. 22 and steps S54 throughS56 in FIG. 28). Generally, in an electronic information device whichuses a battery as its driving source, for energy saving, an automaticpower-off system which automatically turns off the device when therehave been no key operations for a specified time is adopted. In thiscase, if in the photography mode the automatic power-off system works toshut off the power during writing of a live view image on the liquidcrystal display 10, an incomplete image will be continuously displayed,which is ugly.

In including such an automatic power-off task in the control procedurefor the photography mode shown by FIG. 29, as FIGS. 36 and 37 show,steps S70 a, S71 a, S78 a, S78 b and S78 c shall be added. The processesat the other steps in FIGS. 36 and 37 are performed in the same ways asdescribed with reference to FIG. 29.

The automatic power-off system is described. When a supply of electricpower to the image-pick up unit 103 is shut off after image pick-up, anautomatic power-off timer is reset at step S70 a. Thereafter, if no keyoperations are recognized (“NO” at step S71), the timer counts up atstep S78 a, and it is judged from the count value of the timer at stepS78 b whether or not a specified time has passed. If the specified timehas not passed, the processes at step S73 through S77 are performed, andwhen the specified time has passed (with no key operations), a power-offprocess is performed at step S78 c. If any key operation is recognizedat step S71, the automatic power-off timer is reset at step S71 a.

By adopting an automatic power-off system as shown by FIGS. 36 and 37,it never occurs that a power-off process at step S78 c is performedduring image writing on the liquid crystal display 10 (step S63), andwhenever a power-off process is automatically performed, image writingon the liquid crystal display 10 has been completed. Thus, there are nopossibilities that an incomplete picture is continuously displayed.

OTHER EMBODIMENTS

In the embodiments above, memory cards are described as examples ofstorage media. It is, however, possible to provide a liquid crystaldisplay on a surface of an electromagnetic disk or on a surface of afloppy disk. Also, a plurality of liquid crystal displays can beprovided on one storage medium. The material with a memory effect towhich the present invention is applicable is not limited to liquidcrystal and, for example, may be a material which displays color byheat.

Although the present invention has been described in connection with thepreferred embodiments, it is to be noted that various changes andmodifications are possible to those who are skilled in the art. Suchchanges and modifications are to be understood as being within the scopeof the present invention.

1. An electronic information device comprising: a display which uses amaterial having a memory effect, the display having a write mode forwriting an image on the display based on image data and a display modefor displaying the image written in the write mode without electricpower, and when the write mode is interrupted before completion of thewriting of the image, an incomplete image including a part of the imageremains to be displayed on the display in the display mode; an electricpower source for supplying driving power to the display; a first inputmember to be operated by an operator to issue a turn off command to turnoff the electric power source; and a controller which, in response to acommand to turn off the electric power source which is issued while thedisplay is performing writing of an image based on display data byconsuming electric power supplied from the electric power source, turnsoff the electric power source after completion of the writing of theimage which is being written on the display based on the image data whenthe command to turn off the electric power source is issued; whereby thedisplay displays a complete image based on the image data after theelectric power source has been turned off.
 2. An electronic informationdevice according to claim 1, further comprising an image pick-up unitwhich picks up an image of an object by use of an image sensor andproduces the image data.
 3. An electronic information device accordingto claim 1, wherein information written on the display is a thumbnailpicture such that a plurality of thumbnail images can be written side byside.
 4. An electronic information device comprising: a display whichuses a material having a memory effect, the display having a write modefor writing an image on the display based on image data and a displaymode for displaying the image written in the write mode without electricpower, and when the write mode is interrupted before completion of thewriting of the image, an incomplete image including a part of the imageremains to be displayed on the display in the display mode; an electricpower source for supplying driving power to the display; an input memberto be manually operated by an operator to input a specified command; atimer for counting elapsed time; and a controller that resets a timervalued when the manual operation of the input member is conducted, andincrements the timer value when the write mode has been completed;wherein the controller performs the following processes: an automaticpower-off process which turns off the electric power sourceautomatically when a timer value exceeds a predetermined value; wherebythe display displays a complete image based on the image data after theelectric power source has been turned off.
 5. An electronic informationdevice according to claim 4, wherein the input member is a key switch.6. An electronic information device according to claim 4, furthercomprising an image pick-up unit for picking up an image of an object byuse of an image sensor and for producing the image data.
 7. Anelectronic information device according to claim 4, wherein informationwritten on the display is a thumbnail picture such that a plurality ofthumbnail images can be written side by side.
 8. An electronicinformation device comprising: a display using a material having amemory effect, the display having a write mode for writing an image onthe display based on display data and a display mode for displaying theimage written in the write mode without electric power, and when thewrite mode is interrupted before completion of the writing of the image,an incomplete image including a part of the image remains to bedisplayed on the display in the display mode; a first input member whichis manually operated by an operator to input a specified command toinstruct the electronic information device how to operate; and acontroller which, when the first input member is operated while writingof an image based on display data on the display is being performed,invalidates the command sent from the first input member and, when thefirst input member is operated after completion of the writing of animage based on display data, controls the electronic information devicein accordance with the command sent from the first input member; wherebywhen the first input member is operated during writing of an image basedon the display data on the display, the display completely displays theimage which was being written based on the display data when the firstinput member was operated after an electric power source supplying powerto the display has been turned off.
 9. An electronic information deviceaccording to claim 8, wherein the first input member is for inputting acommand to shut off the supply of electric power to the display.
 10. Anelectronic information device according to claim 8, further comprising:a second input member with which an operator can input a command whichis different from the command inputted with the first input member;wherein, the controller controls the electronic information device inaccordance with the command sent from the second input member regardlessof whether or not writing on the display is being performed.
 11. Anelectronic information device according to claim 10, wherein the secondinput member is a shutter button.
 12. A method of controlling anelectronic information device, said method comprising the steps of:writing an image based on display data on a display which uses amaterial having a memory effect by supplying electric power to thedisplay from an electric power source, the display having a write modefor writing an image on the display and a display mode for displayingthe image written in the write mode without electric power, and when thewrite mode is interrupted before completion of the writing of the image,an incomplete image including a part of the image remains to bedisplayed on the display in the display mode; commanding a power-off ofthe electric power source in response to an operating of a first inputmember by an operator; and when a power-off of the electric power sourceis commanded while the display is performing writing of an image basedon display data by consuming electric power supplied from the electricpower source, executing the power-off command after completion of thewriting of the image which is being written on the display based on thedisplay data when the power off of the electric power source iscommanded; whereby when the power off of the electric power source iscommanded while the display is performing writing of an image based ondisplay data, the display displays a complete image based on the displaydata after the electric power source has been turned off.
 13. A controlmethod according to claim 12, further comprising the step of picking upan image of an object by use of an image sensor and producing the imagedata.
 14. A control method according to claim 12, wherein informationwritten on the display is a thumbnail picture such that a plurality ofthumbnail images can be written side by side.
 15. A method ofcontrolling an electronic information device, said method comprising: awrite step of writing an image based on display data on a display whichuses a material having a memory effect by supplying electric power tothe display from an electric power source, the display having a writemode for writing an image on the display and a display mode fordisplaying the image written in the write mode without electric power,and when the write mode is interrupted before completion of the writingof the image, an incomplete image including a part of the image remainsto be displayed on the display in the display mode; an automaticpower-off step of automatically turning off the electric power sourcewhen a timer value of a timer exceeds a predetermined value; anincrement step of the timer value which increments the timer value whenthe write mode has been completed; and a resetting step that resets thetimer value when a manual operation of an input member is operated by anoperator to input a specific command; whereby the display displays acomplete image based on the display data after the electric power sourcehas been turned off.
 16. A control method according to claim 15, whereinthe input member is a key switch.
 17. A control method according toclaim 16, further comprising an image pick-up step of picking up animage of an object by use of an image sensor and producing the imagedata.
 18. A method of controlling an electronic information device, saidmethod comprising the steps of: writing an image based on display dataon a display which uses a material having a memory effect by supplyingelectric power to the display from an electric power source, the displayhaving a write mode for writing an image on the display and a displaymode for displaying the image written in the write mode without electricpower, and when the write mode is interrupted before completion of thewriting of the image, an incomplete image including a part of the imageremains to be displayed on the display in the display mode; issuing aspecified command to instruct the electronic information device how tooperate in response to a manual operation of a first input member by anoperator; and when the first input member is operated while writing ofan image based on display data on the display is being performed,invalidating the command sent from the first input member, and, when thefirst input member is operated after completion of the writing of animage based on display data, controlling the electronic informationdevice in accordance with the command sent from the first input member;whereby when the first input member is operated during writing of animage based on the display data on the display, the display completelydisplays the image which was being written based on the display datawhen the first input member was operated after the electric power sourcehas been turned off.
 19. A control method according to claim 18, whereinthe first input member is for issuing a command to shut off the supplyof electric power to the display.
 20. A control method according toclaim 19, further comprising the steps of: issuing another command byoperating a second input member; and controlling the electronicinformation device in accordance with the command sent from the secondinput member regardless of whether or not writing on the display isbeing performed.
 21. A control method according to claim 20, wherein thesecond input member is a shutter button.
 22. An electronic informationdevice according to claim 4, wherein the electric power source isadapted to supply driving power to the electronic information device,including the display.
 23. The control method according to claim 15,wherein the electric power source is adapted to supply electric power tothe electronic information device, including the display.
 24. Anelectronic information device which functions with a display including awrite mode for writing an image on the display and a display modethereafter for displaying the written image without electric power, andwhen the write mode is interrupted before completion of the writing ofthe image, an incomplete image including a part of the image remains tobe displayed on the display in the display mode, the electronicinformation device comprising: an electric power source for supplyingdriving power to the display; a first input member to be operated by anoperator to issue a turn-off command to turn off the electric powersource; and a controller which, in response to a command to turn off theelectric power source which is issued while the display is performingwriting of an image based on display data by consuming electric powersupplied from the electric power source, turns off the electric powersource after completion of the writing of the image which is beingwritten on the display based on the display data when the command toturn off the electric power source is issued; whereby the displaydisplays a complete image based on the display data after the electricpower source has been turned off.
 25. An electronic information devicewhich functions with a display which uses a material having a memoryeffect, the display which has a write mode for writing an image on thedisplay and a display mode thereafter for displaying the written imagewithout electric power, and when the write mode is interrupted beforecompletion of the writing of the image, an incomplete image including apart of the image remains to be displayed on the display in the displaymode, the electronic information device comprising: an electric powersource for supplying driving power to the display; an input member to bemanually operated by an operator to input a specified command toinstruct the electronic information device how to operate; a timer forcounting elapsed time; and a controller which resets a timer value whenthe manual operation of the input member is conducted, and increment thetimer value when the write mode has been completed; wherein thecontroller performs the following processes: an automatic power-offprocess which turns off the electric power source automatically when atimer value exceeds a predetermined value; whereby the display displaysa complete image based on display data after the electric power sourcehas been turned off.
 26. An electronic information device whichfunctions with a display which uses a material having a memory effect,the display which has a write mode for writing an image on the displayand a display mode thereafter for displaying the written image withoutelectric power, and when the write mode is interrupted before completionof the writing of the image, an incomplete image including a part of theimage remains to be displayed on the display in the display mode, theelectronic information device comprising: a first input member which ismanually operated by an operator to input a specified command toinstruct the electronic information device how to operate; and acontroller which, when the first input member is operated while writingan image based on display data on the display is being performed,invalidates the command sent from the first input member and, when thefirst input member is operated after completion of the writing of animage based on display data, controls the electronic information devicein accordance with the command sent from the first input member; wherebywhen the first input member is operated while writing the image based onthe display data on the display, the display completely displays theimage which is being written based on the display data when the firstinput member is operated after an electric power source supplying powerto the display has been turned off.